GHSA-5mf8-v43w-mfxp

XWiki Platform privilege escalation (PR) from account through AWM content fields

### Impact Any registered user can use the content field of their user profile page to execute arbitrary scripts with programming rights, thus effectively performing rights escalation. The problem is present [since version 4.3M2](https://jira.xwiki.org/browse/XWIKI-7369) when AppWithinMinutes Application added support for the Content field, allowing any wiki page (including the user profile page) to use its content as an AWM Content field, which has a custom displayer that executes the content with the rights of the ``AppWithinMinutes.Content`` author, rather than the rights of the content author. ### Patches The issue has been fixed in XWiki 14.10.5 and 15.1RC1 by https://github.com/xwiki/xwiki-platform/commit/dfb1cde173e363ca5c12eb3654869f9719820262 . The fix is in the content of the [AppWithinMinutes.Content](https://github.com/xwiki/xwiki-platform/commit/dfb1cde173e363ca5c12eb3654869f9719820262#diff-850f6875c40cf7932f40a985e99679a041891c6ee75d10239c06921c0019cf78R82) page that defines the custom displayer. By using the ``display`` script service to render the content we make sure that the proper author is used for access rights checks. ### Workarounds If you want to fix this problem on older versions of XWiki that have not been patched then you need to modify the content of ``AppWithinMinutes.Content`` page to use the ``display`` script service to render the content, like this: ``` - {{html}}$tdoc.getRenderedContent($tdoc.content, $tdoc.syntax.toIdString()).replace('{{', '{{'){{/html}} + {{html}}$services.display.content($tdoc, { + 'displayerHint': 'default' + }).replace('{{/html}}', '{{/html}}'){{/html}} ``` ### References * JIRA issue https://jira.xwiki.org/browse/XWIKI-19906 * Fix https://github.com/xwiki/xwiki-platform/commit/dfb1cde173e363ca5c12eb3654869f9719820262 ### For more information If you have any questions or comments about this advisory: * Open an issue in [Jira XWiki.org](https://jira.xwiki.org/) * Email us at [Security Mailing List](mailto:security@xwiki.org) ### Attribution This vulnerability has been found and reported by @michitux .